This invention relates generally to an apparatus for accurately positioning a massive article disposed thereon, such as a commercial aircraft landing gear, under a separately supported second article, such as under a landing gear bay of a commercial aircraft, to facilitate attachment of the massive article to the second article. More specifically, the invention relates to an article supporting apparatus, which may be in the form of a towable trailer, having an interior frame capable of selective longitudinal and transverse movement on a main frame, wherein the main frame may also be lifted and lowered for accurate positioning of the article under a second article to facilitate attachment and detachment of the two articles.
In the maintenance of large commercial and military aircraft, it becomes necessary from time to time to replace various strut seals on a seal carrier in a strut housing of an aircraft landing gear assembly. To accomplish this task in the prior art, hydraulic jacks are placed under the fuselage and wings of the aircraft, such as, for example, a Boeing 767, and the aircraft is lifted so that the massive landing gear assemblies are suspended above and clear of the aircraft supporting surface. Next, two portable hydraulic jacks are placed on opposite sides of one of the landing gear assemblies, nitrogen gas is then released from the landing gear shock absorbers and the portable jacks are extended to raise the landing gear assembly against the now readily compressible shock absorbers. With the landing gear assembly thus raised, a gland nut on a lower end of the landing gear strut becomes unloaded of weight and can then be readily loosened with a wrench to decouple the strut from its fittings in the aircraft landing gear bay. Thereafter, the portable jacks are retracted to lower the decoupled landing gear to permit access to an upper end of the strut for the purpose of changing the strut seals. Sometimes, however, retraction of the portable jacks alone is insufficient to satisfactorily expose the strut seal carrier, by reason of which it may be necessary to further extend the jacks under the aircraft fuselage and wings to raise the aircraft further until the strut seal carrier becomes sufficiently exposed to permit replacement of the seals.
Once the strut seals have been replaced, the portable jacks are again extended to raise the landing gear strut and, if necessary, the jacks under the wings and fuselage are partially retracted to enable the strut to be properly rejoined to its fittings in the landing gear bay, whereupon the gland nut is tightened and, thereafter, the shock absorbers are recharged with nitrogen gas. Finally, the portable jacks are retracted and removed from the landing gear assembly and the wing and fuselage jacks are further retracted until the landing gear assemblies engage the aircraft supporting surface to securely support the aircraft. The task is time consuming and tedious and the use of the portable jacks is dangerous as they can relatively easily be tipped over with the weight of a one ton or more landing gear assembly resting thereon, often with disastrous consequences to workers and/or to equipment in the area. It is especially dangerous if the portable jacks need to be moved slightly in order to precisely position a landing gear supported thereon in a raised position in order to join the struts to the gear bay fittings.
Sometimes it is necessary to completely remove a landing gear assembly from a large commercial or military aircraft to a remote work station for more thorough inspection and repair than is possible with the strut remaining in close proximity to it""s coupling position in the landing gear bay of the aircraft. In such cases, while the assembly is readily removable to such a remote work station by simply rolling it on its tires, return of the assembly for reattachment to its fittings in the aircraft landing gear bay presents a major problem of precisely positioning the assembly for reattachment due to it being elevated on jacks and due to the extremely close tolerances of the landing gear fittings in the aircraft with the landing gear strut coupling and due to the great weight of the gear assembly.
By means of our invention, the considerable danger to attending workers in using unstable portable jacks to support and elevate massive landing gear assembly and in moving the jacks with the assembly supported thereon is virtually eliminated. Moreover, by means of our invention, the time required in using conventional methods and equipment to replace landing gear strut seals and to precisely position a massive landing gear assembly for attachment under and to a large aircraft is substantially reduced.
It is an object of our invention to provide an apparatus for accurately positioning a massive article disposed thereon, much as a commercial aircraft landing gear, under a separately supported second article, much as a commercial aircraft, to facilitate attachment of the massive article to the second article.
It is a further object of our invention to provide a mobile article supporting and positioning apparatus which includes a longitudinally and transversely movable interior frame within a main frame and further includes means for lifting and lowering the main frame, the interior frame and an article supported on the interior frame.
Briefly, in accordance with our invention, there is provided an apparatus for accurately positioning a massive article disposed thereon under a separately supported second article to facilitate attachment of the massive article to the second article. The apparatus includes a main frame having longitudinally spaced apart opposite ends and transversely spaced apart opposite sides and an interior frame for supporting a massive article thereon which is movably disposed on the main frame. The interior frame is selectively movable, longitudinally, up to a first maximum distance between the opposite ends of the main frame and is also selectively movable, transversely, up to a second maximum distance between the opposite sides of the main frame. The apparatus also includes a first means connected between the interior frame and the main frame for moving the interior frame a selected distance, longitudinally, of up to the first maximum distance between the opposite ends of the main frame. The apparatus further includes a second means connected between the interior frame and the main frame for moving the interior frame a selected distance, transversely, of up to the second maximum distance between the opposite sides of the main frame.
These an other objects, features and advantages of our invention will become apparent to those skilled in the art from the following detailed description and attached drawings upon which, by way of example, only a preferred embodiment of our invention is described and illustrated.